So, while fiddling around I came across the fact that you can pass a fake user-agent to Google Chrome and Chromium at the command line.
An example for Windows users, you could type this into the run dialog box (Windows key + R):
“c:\Program Files\chromeplus\chrome.exe” -user-agent=”Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543a Safari/419.3″
For a list of user agent strings, check out http://www.useragentstring.com/
Of course, an easier way to do it on a regular basis would be to create a shortcut on your desktop.